Changes in pupil size or movement might signal mental health issues such as anxiety, neurological disorders, or drug use.

Human eyes are actually spheres. The part that we can see is only just the front. That coloured circle is called the iris and the black spot in the middle is the pupil. This is the part of the eye ...

Our eyes are typically closed when we ... More information: Manuel Carro-Domínguez et al, Pupil size reveals arousal level fluctuations in human sleep, Nature Communications (2025).

This clip is a look at the human eye and how it works. We illustrate the functions of the eye with models, film clips and magnified images. The eye is a ball with a hole at the front, the pupil ...

When evolution skeptics want to attack Darwin's theory, they often point to the human eye ... the separate parts of the eye -- the lens, the retina, the pupil, and so forth -- since none of ...

They also tend to have pupils that open more widely in low light. So, at the outset, nocturnal eyes gather more light than human eyes do. After the light passes through the pupil, it is focused by ...

Humans optimize effort expenditure even at the level of eye movements by choosing affordable eye movements over costly alternatives and adjusting gaze behavior based on task demands.

Eye tracking plays a critical role in the latest virtual and augmented reality headsets and is an important technology in the ...

They're often described as the 'windows to the soul'. But a new study suggests that our eyes can convey more about us than we ...